Pyrazolyl-5, dimethyl carbamates



- above.

Patented June 22, 1954 UNITED STAT PATENT OFFICE 7 2,681,915 PYRAZOLYL-S, DIMETI-IYL CARBAMATES Hans Gysin, Alfred Margot, and Charles Simon, Basel, Switzerland, assignors to J. R. Geigy A. G., Basel, Switzerland, a Swiss firm No'Drawing. Application December 9, 1952, Serial No. 325,014

Claims priority, application Switzerland August 22, 1949 N CH3 wherein R represents a radical selected from the group consisting of hydrogen, alkyl, lower allicnyl,

lower alkoxyalkyl, lower halogenalkyl, phenyl, p-nitrophenyl, benzyl and wpyridyl, and

R represents a radical selected from the group consisting of hydrogen and lower alkyl.

These compounds are excellently suited for combating pests such as insects and other arthropods and also their stages of development.

The new compounds can be produced, for example by the reaction of dimethyl carbamic acid chloride with 5-Dyrazolones of the general for- -mula:

wherein R and B have the meanings given The reactionmay be performed in the presence of acid binding agents or withsalts of the enol form of the above named compounds.

The reaction may take place in the presence or absence of solvents such as benzene, acetone, dioxan, and acetic acid ethyl ester. Acid binding agents which come into consideration are e. g. potassium carbonate, sodium carbonate, sodium bicarbonate, sodium ethylate or tertiary organic bases such as triethylamine. In particular, the alkali salts are suitable as enol salts.

The following example illustrates the produc tion of the new compounds. Parts are always given as parts by weight and the temperatures are given in degrees centigrade.

Example 1 175 parts of 1-phenyl-3-methy1-5-pyrazolone' 9 carbamic acid chloride are added. Care should be taken that the reaction does not take place too vigorously, by cooling if necessary. On completion of the reaction, the mixture is heated to boiling for 10-12 hours, and the water which is so formed is removed in a separator. The reac-' tion mixture is then cooled, and 400 parts of water and enough potassium carbonate solution is added so that the reaction of the watery solution definitely remains phenolphthalein alkaline after thoroughly shaking with the benzene layer. After separating off the watery part, the benzene solution is Washed with water until a neutral reaction is obtained, then the benzene is distilled off. After removal of some unchanged dimethyl carbamic acid chloride, the l-phenyl-3-methylpyrazolyl-(5) dimeth-yl carbamate boils at 160- 162 at 0.2 mm. pressure. I In a pure form, the substance melts at 50.

The following compounds can be produced in the same manner:

General Formula R(l'.| fiJH /CH N\ /C OC O'N I |T CH3 R B. P. at No. R l R mm M. P.

97688 1.--- .H H 135 0.1 2...- l'l-CzHv H 110 0.6 3.--. J. ISO-03H? H 0. O4 4..-. 11-O4H9 H 0. 05 5.... iS0-C4H0 H 112 0. 1 6.... sec-04H H 113' 0.12 7-.-. ll-Cs u H 115 0.2 8.... lSO-GsHn H 112 O. 2

CH2=CHOH2 H 108 0. 1 10... C2H5OCH2CH2 H ll.-. CeHs H 148 0.5 12... CH3 103 0.3 CH3 CH3 102 O. 6 14... C2115 CH3 115 0. 5 15.. l'l-G3H7 CH3 110 0.3 10... 180-03117 CH3 107 0. 15 17... n-CaHu CH3 106 0.35 18... 1SO-O4H0 CH3 124 0. 4 19... sec-C4119 CH3 108 0.2 20... tcrt. GAHQ CH3 100 0.22 21... n-CsHu CH3 118 0. 1S 22... iSO-CsHu CH3 131 0.5 23... HCBHIJ CH3 24... II- E H CH3 0.2

25... n-C4Hr'CH-CH2OH CH3 26... CHz CH-CHz 0H3 27... CHaCH=CHCHz- CH3 28... CH2=CCH2- CH3 29... 5' F-CH2CH2 CH3 30... OH3-O,CHr-GHz- CH3 31... C2H5-O-OHg'-CH CH3 32... p-NO2.-CoH4 CH3 33... CGH5-OH2 CH 35-.. H CzHs 36... C2 5 C2115 37... C6115 C2115 38... H H-O3H7 39... CH: 'n-CaH The biological properties of the new compounds are useful in various fields of pestcontrol and the mode of employment depends entirely on the intended use. The active compounds can be used as such, e. g. in powder form, in the form of gas or mist or as smoke. For most purposes, however, it is more economical to combine them with suitable carriers and distributing agents. A number of such substances suitable for the usual forms of application such as dusting agents, spraying agents (suspensions), solutions, aerosols, emulsions and semi-solid preparations (ointments) are given below.

As solid pulverulent carriers may be used, c. g. calcium carbonate, in the form of whiting or ground limestone, kaolin, bole, bentonite, talcum, powdered magnesia, kieselguhr, boric acid, tricalcium phosphate, also powdered wood, powdered corl; and other materials of a vegetable nature. the addition of wetting agents and protective colloids the pulverulent preparaions can be suspended in water and used as spraying agents. The active substance can be combined. with the carrier for example by impregnating the carrier with solutions of the active ingredients, by mixing the molten active ingreclients with the carriers, or by milling the components together.

Solutions (for spraying) in high boiling carrier solvents such as kerosene and similar mineral oil fractions, in methyl naphthalenes, xylenes, etc. are best suited for direct spraying of objects. They can also be used for impregnating wood. Solutions in lower boiling solvents such as trichloroethylene, tetrachlorethane, ethylene chloride are most suitable for spreading the active ingredient in the form of a mist. The latter solvents, and also, for example, benzine, xylene and chlorobenzene are also suitable for the impregnation of textiles. The active substances are soluble in water to some extent. Water, therefore, if required with the addition of solvents, also comes into consideration as a carrier-solvent and also water soluble organic solvents such.as alcohol or acetone.

Fluoro-trichloromethane and difluroro-dichlorcmethane are examples of solvents and propelling agents for aerosols.

As emulsifying agents there come into consideration those of a cation-active nature such as quaternary ammonium compounds, anion-active agents such as soap, soft soap, resin soap, aliphatic monoesters of sulphuric acid and aliphatic aromatic sulphonic acids, and also nonionogenic emulsifying agents such as higher molecular ethylene oxide condensation products. They are mixed to an emulsiiiable concentration wit the active ingredients with or without the addition of suitable solvents such as e. g. acetone, alcohols, cyclohexanone, benzene, toluene, xylene, tetrahydronaphthalene, alkylated naphthalenes, phthalic acid esters, mineral and vegetable oils, resins, and if required, water.

Petroleum jelly and other ointment bases in which the active ingredient can be incorporated are examples of semi-solid distributing agents.

The active ingredients can also be used together with attractives or lures to form a bait, such as, e. g. sugar, for example in the form of dusting agents with sugar as the main carrier, or spraying agents or in the form of fly-papers.

The various forms of application can generally be adapted to the intended use by the addition of substances which improve the distribution, the adhesive properties and resistance to rain on the treated surface, such as, e. g. fatty acids, resins, wetting agents, glue, casein or alginates. The biological activity can also be increased by the addition of substances with bactericidal, fungicidal or also insecticidal properties.

As bactericidal substances that can be added come into consideration, e. g. chlorinated phenols and quaternary ammonium compounds; suitable fungicidal compounds include e. g. sulphur in its various forms of application, such as limesulphur liquid, copper compounds such as copper oxychloride or Bordeaux liquid and fluorides. As examples of further insecticidal compounds may be named: synthetic products like 1.1-bis- (p-chlorophenyl)-2.2.2-trichlorethane, -hexachlorocyclohexane, p-nitrophenyl-di-ethyl-thiophosphate, tetra-ethyl-pyrophosphate, chlorinated camphene, 1.2.4.55.7.8.8-octachlorol.7- methano-3a.4.'1.7a-tetrahydroindane and 5.5-dimethyl-dihydroresorcinol-dimethyl carbamate. Pyrethrin and rotenone are suitable vegetable products.

Example 2.--Du.s.ting agent 1 part of active ingredient, e. g. 3-methyl-pyrazolyl-(5) -dimethyl carbamate is ground asfinely as possible with 99 parts of talc. The adhesive properties of this powder can be increased by the addition of 2 parts of a liquid fatty acid and 1 part of quenched lime. This dusting agent can be used, for example, to combat pests in plant protection and in the household. In this form, the agent can also be used for protection of storerooms, either by dusting or mixing it with the goods themselves.

Eatample 3.-Spraymg agent 25 parts of active ingredient, e. g. l-isopropyl- 3-methyl-pyrazolyl-(5) -dimethyl carbamate, 35 parts of kaolin, 30 parts of a porous carrier, e. g. colloidal silicic acid and 10 parts of sulphite waste liquor are pulverised as finely as possible. On stirring with water, a very suitable spraying agent is obtained for cornbatting flies in stalls where animals are kept.

Example 4.Strewing agent 1 part of active ingredient, e. g. l-phenyl-3- methyl-pyrazolyl-(5)-dimethyl carbarnate is mixed with 99 parts of coarse grained carbonated lime. This sprinkling agent is suitable everywhere where a finely pulverised agent cannot be used because of dust formation, e. for combatting snails in market gardens.

Efnample 5.-Sprin7cling agent (spray) (a) 2 parts of active ingredient, e. g. 1(p nitrophenyl) 3 methyl-pyrazolyl(5) clirriethyl carbarnate are dissolved in 10 parts of xylene and 88 parts of kerosene.

(b) 2 parts of active ingredient, e. g. 1-phenyl- 3m-ethylpyrazolyl-( 5) dimethyl carbamate and 3 parts of 1.1-bis-(p-chlorophenyl) -2.2.2-trichlorethane are dissolved in 10 parts of xylene or another mutual solvent and parts of kerosene.

Both solutions are excellently suited for combatting flies in the household and also in store rooms and slaughterhouses.

(c) 10 parts of 3-methyl-pyrazolyl-(5) -dimethyl carbamate are dissolved in 90 parts of ethyl alcohol or isopropyl alcohol. This solution is diluted to 0.1% with water for use in plant protection, particularly in combatting leaf aphids. The properties of the solutions can beimproved by the addition of wetting agents and other additives such as adhesives.

(d) parts of active ingredient, e. g. 1-ethyl- 3-methyl-pyrazolyl- (5) -dimethyl carbamate and 4 parts of an ethylene oxide condensation product are dissolved in 43 parts of Water and 43 parts of isopropyl alcohol. This concentrate is diluted to 0.1% with water and is especially suitable for combatting leaf aphids.

Example 6.F2tmz'gating agent parts of active ingredient, e. g. l-n-propylpyrazc1yl- (5)-dimethyl carbamate are mixed with 61 parts of sawdust which has previously been impregnated with 18.4 parts of potassium nitrate. The mass is shaped into tablet form under ressure.

The insecticidal smoke formed by burning the tablets is especially suitable for combatting in sects in enclosed spaces.

Example 7 .Emulsion (a) 20 parts of active ingredient, e. g. 1- phenyl pyrazolyl (5) dimethyl carbamate, parts of acetone, 20 parts of xylene and parts of a higher molecular condensation product derived from a fatty alcohol and ethlyene oxide are dissolved together.

(b) parts of l-phenyl-3-methy1-pyrazolyl- (5) -dimethyl carbamate, 20 parts of dia-oetone alcohol and 30 parts of a higher molecular condensation product derived from a fatty alcohol and ethylene oxide are dissolved together.

On stirring up With water, emulsions with an insecticidal action are obtained which are suitable for combatting leaf aphids.

It should be noted that also leaf aphids which are not in direct contact with the active substance will also be killed, as the substance penetrates into the sap-stream of the plants and therefore kills all sap-sucking insects.

If the emulsion, suitably diluted, is sprayed on to the earth, then it is possible to kill leaf aphids and other sap-sucking insects on the plants which take up the substance through their roots.

By making special additions to the above emulsions evaporation of the active substance can be prevented and the resistance to rain increased. In this way it is possible to attain a certain permanent action against leaf aphids as new amounts of active ingredient are continually penetrating into the sap-stream from the deposits of previous sprayings.

Natural and artificial resins, dextrin, starch,

waterg'lass, adhesives etc. are suitable additives, for the above mentioned purpose.

Example 8.-Fo1' use in mist apparatus 20 parts of active ingredient, e. g. l-ethyl-3 methyhpyrazolyh 5) -dirnethy1 carbamate dissolved in volatile solvents such as acetone. carbon tetrachloride, trichlorethylene. are sprayed in mist apparatus under strong air pressure. This form of application is particularly suitable for combatting leaf aphids in large orchards.

Example 9.--Gas l isoarnyl 3-methyl pyrazolyl-(5) -dimethyl carbarnate either as such or with suitable additives which help vaporisation by heating, e. g. on an electrically heated plate, is evaporated and in this way kills insects in enclosed spaces.

What We claim is:

1. As new chemical compounds, the dimethyl carbamates of the general formula:

1T1 CHI N CH3 wherein R represents a radical selected from the group consisting of hydrogen, alkyl, lower allower halogenalkyl, phenyl, p-nitrophenyl, benzyl and e-pyridyl, and R represents a radical selected from the group consisting of hydrogen and lower alkyl.

3. As a new chemical compound, the l-phenyl- 3-methyl-pyrazolyl- (5) -dimethy1 carbamate.

4. As a new chemical compound, the l-isopropyl-3-methyl-pyrazolyl- (5) dimethyl carbamate.

5. As a new chemical compound, the S-methylpyrazolyl- (5) -dimethyl carbamate.

No references cited. 

1. AS NEW CHEMICAL COMPOUNDS, THE DIMETHYL CARBAMATES OF THE GENERAL FORMULA: 